I have only taken my car to Crown(to answer the guys who asked before). I called a dealer in Dallas,that I used to do business with when I lived there,(Park Place) that told me thay have seen several 90-95 cars with the 3.5 Liter diesels need short block and/or ring replacement. Many I was told in under 50K. he recommended that before I pay for engine work to run some 10W oil through to try to "set" the rings?. He thought this problem in these engines started with rings that didn't ever seat properly...any ideas?